Ochoco Mountains

Ochoco Mountains
Range
Steins Pillar
Country United States
State Oregon
Part of Blue Mountains province
Highest point Lookout Mountain (Oregon)
 - elevation 6,926 ft (2,111 m)
 - coordinates
Length 114 mi (183 km), North-South
Width 86 mi (138 km)
Area 4,889 km2 (1,888 sq mi)
Geology Uplifted accreation, and volcanic
Period Permian, Triassic, Jurassic, and Eocene

The Ochoco Mountains are a mountain range in central Oregon. The Ochoco Mountains form the western end of the Blue Mountains province. The mountains were formed when Permian, Triassic, and Jurassic rocks were slowly uplifted by volcanic eruptions to form the Clarno Formation. Today, the highest point in the range is Lookout Mountain. The dominant vegetation on the west side of the range is old growth Ponderosa pine; on the east side Western juniper is common. The western area of the Ochoco Mountains is administered by the Ochoco National Forest. The southeastern part of the range is part of the Malheur National Forest. The Ochoco Mountains are an excellent area for hiking, camping, bird watching, rockhounding, and hunting as well as cross-country skiing in the winter.

Contents

Geology

The Ochoco Mountains in central Oregon form the western end of the Blue Mountains province. The Blue Mountains are not a single cohesive range, they are a complex of mountain ranges and inter-mountain basins and valleys which extend from the northeast corner of Oregon southwestward into central Oregon ending near Prineville. The Ochoco portion of the province is part of a wide uplifted plateau, made of rocks from the Permian, Triassic, and Jurassic periods (300 to 200 million years old) which were transported by the Pacific Plate and accreated in the late Mesozoic era (about a 100 million years ago) as part of a vast shallow sea, and then slowly uplift by volcanic eruptions during the Eocene epoch (50 to 37 million years ago) to form the Clarno Formation. From 37 to 17 million years ago, eruptions in the western Cascades spread ash across eastern Oregon, forming the John Day Formation. From 17 to 14 million years ago, major volcanic eruptions covered much of the province with the basalt flows that comprise the Columbia River Basalt Group. Since then, continued faulting and uplift has resulted in a deeply eroded landscape. Stein’s Pillar is an excellent example of this erosion.[1]

During the Eocene epoch, central Oregon volcanoes deposited layers of lava and ash up to 1,000 feet (300 m) thick over the area that is now the Ochoco Mountains. Large mudflows called lahars were also common during that period. These mudflows often covered and preserved the plants and animals, resulting in fossil beds. Today, fossils of prehistoric trees, fruits, nuts, and flowers can be found in the Ochoco Mountains along with fossilized animals including horses, camels, rhinoceros, and hippopotamus.[2]

Topography

The Ochoco Mountain covers an area of 4,889-square-mile (12,660 km2), running 114 miles (183 km) north to south and 86 miles (138 km) east to west.[3] The eight highest peaks in the range are:

Ecology

The vegetation in the Ochoco Mountains ranges from old growth Ponderosa pines on the western slopes and in the mountain valleys to western juniper and sagebrush on the eastern and southern slopes. The high mountain meadows host a wide variety of wild flowers and even ferns in some areas. Big Summit Prairie near the center of the Ochoco Range is well known for its spring wild flowers displays.[4]

Ponderosa pine is the dominant tree species in most parts of the Ochoco Mountains. These pines are common at elevations from 3,000 to 6,100 feet (1,900 m) above sea level. Manzanita, antelope bitterbrush, and ceanothus are common shrubs in the pine-dominated areas with Idaho fescue and Ross' sedge as the main ground cover. Ponderosa pine forests are tolerant of drought and are adapted to survive low-intensity wildfires. Birds commonly found in the pine forests of the Ochoco Mountains include the northern flicker, hairy woodpecker, red-tailed hawk, and Steller's jay. Central Oregon’s ponderosa pine forests are an important winter range for mule deer and Rocky Mountain elk.[5]

On the dryer eastern side of the Ochoco Mountains, the Western juniper trees survive on as little as eight inches (203 mm) of precipitation per year. The Ochoco’s juniper woodland cover wide areas from 3,000 to 4,300 feet (1,300 m) in elevation. Antelope bitterbrush and sagebrush are common shrubs in these areas with Idaho fescue and bluebunch wheatgrass as the main ground cover. Juniper woodlands are home to mountain bluebirds, Townsend's Solitaires, and ferruginous hawks during the spring and summer. There are also many small mammals and lizards that are prey for coyote.[5]

Big Summit Prairie is a large high country meadow in the middle of the Ochoco Mountains. Big Summit meadow covers twenty square miles. The prairie is covered by water-loving grasses, overgrown by willows and shrubs in some areas. Tufted hairgrass, elephant's head, and horsetail are common ground cover in the vast meadow land. Quaking aspen with shrubby undergrowth attract wildlife not found in other parts of the Ochoco Mountains. Common birds include sandhill crane, Wilson's Snipe, long-billed curlew, and northern harrier. Even the rare dickcissel has been sighted at Big Summit Prairie. Larger animals include mule deer, pronghorn antelope, Belding's ground squirrel, Northern Pocket Gopher, meadow mice, and coyotes. Also, Rocky Mountain elk move into the area in the fall.[6][7]

Big Summit Prairie is particularly well known from its wildflowers and butterflies. From April through June, flowers cover Big Summit meadow. The first wildflowers to bloom are usually grass widow, wild parsley, and shooting stars. From May through June, Wyethia, buttercups, and camas display their colors. In drier areas, bitterroot bloom with large white and pink flowers. In June and July, other flowers take over the display including Missouri iris, larkspur, Indian paintbrush, checkermallow, and arrowleaf balsamroot. One notable plant is Peck’s Mariposa Lily, a type of Calochortus with lavender petals. This plant is found only in the Ochoco Mountains. Butterfly species common to the Big Summit Prairie include hairstreak, skipper, Eastern tailed-blue, Lycaenidae, checkerspot, fritillary, swallowtail, admiral, and tortoiseshell.[6][7]

Human uses

Most of the Ochoco Mountains are public lands, administered by the United States Forest Service. The Ochoco National Forest is responsible for most of the mountain area; however the southeastern part of the range in the Malheur National Forest. Some land in the Ochoco area is also administered by the Bureau of Land Management. Hiking, fishing, camping, hunting, horseback riding, bird watching, and rockhounding are all popular activities.[8]

The Ochoco National Forest maintains 27 campgrounds in or near the Ochoco Mountains. The largest are Antelope Flat Reservoir, Ochoco Divide, Walton Lake, and Wildcat campground.[9] The Malheur National Forest has several campgrounds in the Ochoco Mountains as well. The largest is the campground at Delintment Lake.[10]

The unique geology of the Ochoco Mountains has resulted in a wide variety of rock types being located in a relatively small area. This brings rockhounds to the area every summer. The Bureau of Land Management and the Ochoco National Forest both have designated areas where rockhounds can search for agate, jasper, petrified wood, petrified moss, and dendrite. These rock collection sites are for personal use only, gathering rocks for commercial purposes is prohibited. Thundereggs can be found at Whistle Springs. Even though the area has been worked by rockhounds for many years, quality thunder eggs are still found at the site. There are also some rare rocks and minerals found in the central Oregon in or near the Ochoco Mountains including opals, amethyst, gem quality calcite, cinnabar, selenite, gypsum, and amygdaloid nodules.[16][17]

Wilderness areas

The Ochoco National Forest has three wilderness areas in the Ochoco Mountains. They are Bridge Creek Wilderness, Black Canyon Wilderness, and Mill Creek Wilderness.

References

  1. ^ "Blue Mountain Province", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Bend, Oregon, 10 March 2005.
  2. ^ "Additional Points of Interest - Geology of Central Oregon", Prineville Crook County Chamber of Commerce, Prineville, Oregon, 2 April 2009.
  3. ^ a b "Ochoco Mountains", Peakbagger.com Database, Geographic Research Systems, Peakbagger.com, Seattle, Washington, 2 April 2009.
  4. ^ Walton, Aaron, "Ochoco Mountains – Central Oregon", Wonder the West, www.wanderthewest.com, Bend, Oregon, 2 April 2009.
  5. ^ a b "Habitats", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 11 March 2004.
  6. ^ a b "Big Summit Prairie", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 29 March 2004.
  7. ^ a b "Big Summit Prairie", Rangeland Management Botany Program, United States Forest Service, United States Department of Agriculture, Washington, D.C., 24 June 2008.
  8. ^ "General Info", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 29 August 2006.
  9. ^ "Lookout Mountain Ranger District", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 28 May 2008.
  10. ^ "Developed Campgrounds", Malheur National Forests, United States Forest Service, United States Department of Agriculture, John Day, Oregon, 19 June 2007.
  11. ^ "Antelope Flat Reservoir", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 22 July 2004.
  12. ^ "Ochoco Divide Campground", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 5 August 2008.
  13. ^ "Walton Lake Campground and Trailhead", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 24 June 2008.
  14. ^ "Wildcat Campground", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 17 May 2005.
  15. ^ "Delintment Lake Campground", Malheur National Forests, United States Forest Service, United States Department of Agriculture, John Day, Oregon, 19 June 2007.
  16. ^ "Rockhounding", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 7 February 2006.
  17. ^ "Whistle Springs", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 23 February 2005.
  18. ^ "Bridge Creek Wilderness", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 16 August 2004.
  19. ^ "Black Canyon Wilderness", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 16 August 2004.
  20. ^ "Mill Creek Wilderness", Deschutes and Ochoco National Forests, United States Forest Service, United States Department of Agriculture, Prineville, Oregon, 16 August 2004.

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